1. Field of the Invention
The present invention relates to an airbag device for installation on a vehicle. In particular, the present invention relates to an airbag device suitable for the so-called knee airbag aimed at protection of occupant's lower leg regions.
2. Related Technology
Vehicles such as automobiles are provided with an airbag system in which a bag is rapidly inflated by gas to prevent the occupants from colliding with dangerous zones, thereby minimizing or preventing injuries or death occurring when the occupant hits a hard part inside the vehicle, such as a steering wheel of front glass, during collision.
When the vehicle collides, the occupant is moved forward by the inertia force and the occupant's knees strike against the instrument panel. In order to protect the occupant from such an impact, an airbag device that inflates from the lower surface of the instrument panel has been suggested.
It is desirable that an airbag device could safely restrain the occupant even in cases with different sitting postures of the occupant (for example, a posture close to the instrument panel). However, according to the invention described in Japanese Patent Application Publication No. 10-315894, when the occupant is abnormally close to the instrument panel, the airbag may cause significant damage to the occupant.